LOW-COST SYSTEM FLUSHING
HVP tests a central heating flushing pump from Descale Direct.


The increasing number of condensing boiler installations is making many aware of the perils of connecting a new high efficiency appliance to an old, dirty central heating system.

Cast iron boilers are very forgiving of system sludge, but condensing boilers with their more efficient, but narrower waterways, are much less so.
Indeed, a system flush before fitting any new boiler is a Benchmark requirement and some high efficiency boiler manufacturers' now insist on a system flush as one of their warranty requirements. For these reasons many installers are now investing in a system flushing pump as part of their basic kit.

THE FREDDY PLUS
A recent addition to the range of flushing kits now available is the Freddy Plus from Descale Direct. The Freddy Plus is based on the company's earlier Freddy the Flusher model and is designed to operate as a relatively inexpensive medium-duty machine for the installer who might only clean two or three systems a month.

Units are purchased direct from the company so avoiding 'merchants mark-ups' and special discount packages are available that also include Fernox Restorer and a Fernox TDS Meter.

HVP was given the opportunity to test a Freddy Plus and we gave the unit to Surrey installer, Ralph Elsey to see what he thought of it. Most of Ralph's workload consists of boiler servicing and repair but he has been looking for a relatively low-cost flushing unit to add to his tool kit.

The Freddy Plus has a 0·4hp motor operating from a normal domestic 13A electrical supply and comes with a selection of ready-assembled hoses and 1½" pump adaptors. The Freddy Plus is rated to 35ºC and is, according to Descale Direct, compatible with all proprietary central heating cleaners. The unit's tank has a capacity of 25 litres and is translucent allowing the operator to monitor the fluid level. In addition fill and dump valves are fitted to the machine making it "easy and convenient" to control all aspects of the flushing process, a reverse flow switch also being provided to help ensure a "fast and thorough" flush.

THE TEST
To put the Freddy Plus through its paces Ralph used it on a 13-radiator central heating system that was roughly 21 years old.

The ideal place to connect a flushing pump to a central heating system is across the pump. The pump in this case was readily accessible and once it had been removed the Freddy's hoses were attached using the 1½" pump adaptors. In some properties access to the pump might be difficult and in these cases the connection can be made across a radiator.

Once the connection was made Ralph used the Freddy Plus to run system cleaner through the entire system for ten to fifteen minutes, then concentrated on cleaning individual radiators. All the radiators were isolated bar one and the Freddy was used to circulate cleaner through this single radiator for ten to fifteen minutes. The process was then repeated to give each radiator a thorough flush. The next step was to dump the old dirty system water and top-up with fresh water from the mains. Again this was done for each radiator individually. Once the change of water had been completed all the radiators were opened up and system inhibitor was circulated through the pipework for 20 minutes.

In total the entire operation took about five hours.

THE VERDICT
Ralph had used other system flushing pumps in the past and was extremely complimentary about the performance of the Freddy Plus. The overall quality of the pump and fittings was good and the hose lengths were very generous making it easy to set up the pump in a convenient location. The fact that the unit had an overflow was also appreciated as it allowed the flush to be a one-man job ­ no need to have a mate making sure the tank didn't overflow while you were going round the house dealing with individual radiators.
There was also a facility that enabled the Freddy to run mains-pressure water through the system and Ralph thought that this, together with the reverse-flow switch, would be very useful in dislodging heavy sludge deposits.

Of particular use was the Fernox TDS meter supplied as part of Descale Direct's 'discount package'. The digital meter was used to monitor the level of cleaner remaining in the system while fresh water was flushed through. It's important to remove all traces of cleaner from the system and the easy-to-use tds meter took the guess-work out of the process.

All in all Ralph was very impressed by the performance of the Freddy Plus but he did acknowledge that an installer who did a lot of flushing might prefer a more highly-featured unit. In these cases Descale Direct recommends the "heavy duty" Fernox Powerflow system that offers high temperature cleaning - a machine that is also available through the company.